The contribution of pain and depression to self-reported sleep disturbance in patients with rheumatoid arthritis.

1Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. pnicassio@mednet.ucla.edu

Abstract

The objective of this article is to assess the contribution of disease activity, pain, and psychological factors to self-reported sleep disturbance in patients with rheumatoid arthritis (RA), and to evaluate whether depression mediates the effects of pain on sleep disturbance. The sample included 106 patients with confirmed RA who participated in an assessment of their disease activity, pain, psychological functioning, and sleep disturbance during a baseline evaluation prior to participating in a prospective study to help them manage their RA. Self-measures included the Rapid Assessment of Disease Activity in Rheumatology, the SF-36 Pain Scale, the Helplessness and Internality Subscales of the Arthritis Helplessness Index, the Active and Passive Pain Coping Scales of the Pain Management Inventory, the Center for Epidemiological Studies Depression Scale, and the Pittsburgh Sleep Quality Index. Hierarchical multiple regression analysis confirmed that higher income, pain, internality, and depression contributed independently to higher sleep disturbance. A mediational analysis demonstrated that depression acted as a significant mechanism through which pain contributed to sleep disturbance. Cross-sectional findings indicate that pain and depression play significant roles in self-reported sleep disturbance among patients with RA. The data suggest the importance of interventions that target pain and depression to improve sleep in this medical condition.

Relationship Between Pain, Depression, and Sleep DisturbanceNote. The figure illustrates direct relationships between pain and sleep disturbance, and between depression and sleep disturbance. The relationship between pain and sleep disturbance is partly mediated by depression, as reflected by the path from pain to depression, and the path from depression to sleep disturbance. Although attenuated, the relationship between pain and sleep disturbance remains significant after controlling for depression.a before accounting for depression, b after accounting for depression*p < .05; ** p < .001.